The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 2004
Filed:
Feb. 28, 2003
Jun Tabota, Toyama-ken, JP;
Murata Manufacturing Co. Ltd., Kyoto, JP;
Abstract
An acceleration sensor includes a piezoelectric element and a support member for supporting the piezoelectric element at both longitudinal ends thereof. The piezoelectric element includes a laminate having a plurality of piezoelectric layers. An intermediate piezoelectric layer is a dummy layer which generates no charge when acceleration is applied thereto. Each of the two outer piezoelectric layers includes four longitudinally aligned regions separated at two borders and one central border where stress is inverted when the acceleration is applied. The two outer piezoelectric layers are polarized in the direction of thickness of the piezoelectric element such that cells adjacent to each other in the longitudinal direction of the piezoelectric elements have opposite polarization directions and such that cells aligned with each other in the direction of thickness have the same polarization. Electrodes are arranged on the top and bottom major surfaces of the piezoelectric element and between the piezoelectric layers so that two cells on one side of the central border are connected in parallel with the other two cells on the other side of the central border are connected in parallel in each of the two outer piezoelectric layers, and so that the two parallel-connected cells in the one side are serially connected with the other two parallel-connected cells on the other side. At least one of the electrodes on each of the top and bottom major surfaces and between the layers extends to different longitudinal end surfaces of the piezoelectric element.